Answer:
A) ( - 200t + 40 ) volts
B) b) anticlockwise , c) anticlockwise , d) clockwise , e) clockwise
Explanation:
Given data:
magnetic flux (Φm) = 5.0t^2 − 2.0t
number of turns = 20
<u>a) determine induced emf </u>
E = - N 
= - N ( 10t - 2 ) = - 20 ( 10t - 2 )
= - 200t + 40 volts
<u>b) Determine direction of induced current </u>
i) at t = 0
E = - 0 + 40 ( anticlockwise direction )
ii) at t = 0.10
E = -20 + 40 = 20 ( anticlockwise direction )
iii) at t = 1
E = - 200 + 40 = - 160 ( clockwise direction)
iv) at t = 2
E = -400 + 40 = - 360 ( clockwise direction )
Use of electromagnetic because it moves very faster than others for example xrays theynar very very slow so that not It it is d.
Opposite charges attract
Like charges repel
Answer:
38.67 N
Explanation:
v = Final velocity = 40 m/s
u = Initial velocity
m = Mass of ball = 0.145kg
s = Displacement of ball = 3 m
Equation of motion

F=ma

∴ Average force that a baseball pitcher's hand exerts on the ball is 38.67 N